package com.googlecode.continuity.core.server.hibernate;

import java.io.Serializable;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Types;
import java.util.Properties;

import org.hibernate.HibernateException;
import org.hibernate.usertype.ParameterizedType;
import org.hibernate.usertype.UserType;
import com.googlecode.continuity.core.client.Enum;

/**
 * An EnumUserType describes a method with which enumerations are persisted in hibernate.
 * Source and more information from: http://www.hibernate.org/288.html, originally written by saket_ag.
 *
 * @author Peter Schmitt <aragos@aragos.de>
 */
public class EnumUserType implements UserType, ParameterizedType {

  private static final int[] SQL_TYPES = new int[]{Types.INTEGER};
  private Class targetClass;

  public void setParameterValues(Properties parameters) {
    String targetClassName = parameters.getProperty("targetClass");
    try {
      targetClass = Class.forName(targetClassName);
    } catch (ClassNotFoundException e) {
      throw new HibernateException("Class " + targetClassName + " not found ", e);
    }
  }

  public int[] sqlTypes() {
    return SQL_TYPES;
  }

  public Class returnedClass() {
    return targetClass;
  }

  public boolean equals(Object x, Object y) throws HibernateException {
    return (x == y);
  }

  public int hashCode(Object x) throws HibernateException {
    return x.hashCode();
  }

  public Object nullSafeGet(ResultSet rs, String[] names, Object owner) throws HibernateException, SQLException {
    int value = rs.getInt(names[0]);
    return rs.wasNull() ? null : Enum.get(value);
  }

  public void nullSafeSet(PreparedStatement st, Object value, int index) throws HibernateException, SQLException {
    if (value == null) {
      st.setNull(index, Types.INTEGER);
    } else {
      st.setInt(index, ((com.googlecode.continuity.core.client.Enum) value).getValue());
    }
  }

  public Object deepCopy(Object value) throws HibernateException {
    return value;
  }

  public boolean isMutable() {
    return false;
  }

  public Serializable disassemble(Object value) throws HibernateException {
    return (Serializable) value;
  }

  public Object assemble(Serializable cached, Object owner) throws HibernateException {
    return cached;
  }

  public Object replace(Object original, Object target, Object owner) throws HibernateException {
    return original;
  }
}
